TrailInert

TrailInert is a mobile app that keeps your position estimate moving when GPS is blocked or unreliable (canyons, dense forest, tunnels, urban canyons). It uses phone IMU sensors (accelerometer/gyro), step detection, barometer-based elevation changes, and optional map-matching to trails/roads to produce a continuously updated “best guess” location with a clearly displayed uncertainty radius. The app is brutally transparent: it shows drift growth over time, prompts quick recalibration actions (stand still, take a known heading, tap a known landmark), and logs a breadcrumb track for later export. It also supports offline vector maps and a low-power mode for long outings. This is a traditional app with light AI components for sensor fusion tuning and step/stride estimation; it’s not a magic replacement for GPS, but it can bridge gaps and reduce panic when signal drops.